Tool turret

ABSTRACT

The invention relates to a tool turret, comprising a tool disk ( 2 ), which can be swiveled about a support column ( 32 ) that defines a swivel axis ( 26 ) into positions in which at least one machining tool that can be fastened to the tool disk ( 2 ) is in a machining position, and comprising a drive device ( 14 ), the driving means ( 8, 10 ) of which can be connected by means of a controllable coupling device ( 18 ) to output means ( 20, 22 ), which are used to drive the tool disk ( 2 ) or the machining tool. Said tool turret is characterized in that the drive device ( 14 ) is arranged inside the tool disk ( 2 ) together with the driving means ( 8, 10 ) and the output means ( 22 ) used to drive the machining tool and in that the output means used to drive the tool disk ( 2 ) in a swiveling manner have a gear train arrangement ( 34 ) outside the tool disk ( 2 ) on the support column ( 32 ). The gear train arrangement has an output shaft ( 70 ) that extends along the support column ( 32 ).

The invention relates to a tool turret comprising a tool disk, which can be swiveled around a support column, which defines a swivel axis, into positions in which at least one machining tool that can be fastened to the tool disk is in a machining position, and comprising a drive device having drive means, which can be connected to output means, which are used to drive the tool disk or the machining tool by means of a controllable coupling device.

Such tool turrets are used in industrial manufacturing, especially if the objective is to be able to not only swivel the tool disk in order to select the machining tool required for the current machining operation, but also drive a rotating machining tool by means of a common drive device.

U.S. Pat. No. 7,475,463 B1 discloses a cutting machine tool that uses a common drive device that selectively drives a tool disk or a rotating machining tool, which is fastened to the tool disk by means of a holding mechanism. Thus the prior art solution provides that a shaft, which is driven by the drive device and is provided with two drive means in the form of teeth that are arranged so as to be axially offset relative to each other, is moved into a first or second axial position for the purpose of selectively driving the tool disk or the machining tool. In a first axial position of the shaft, the first drive means of the shaft are uncoupled from the first output means in order to drive the machining tool; and the second drive means in the form of external teeth are in engagement with an output means, which permits the tool disk to be swiveled. In a second axial position of the shaft, the first drive means that are provided on the shaft for driving the machining tool are brought into engagement with the drive means for driving the machining tool, so that the latter can be moved rotationally. The prior art solution is relatively large in size, so that the tool turret has the drawback that its range of application is extremely limited.

Based on this state of the art, the object of the present invention is to provide a tool turret that is distinguished by a simple, compact, and reliable design that meets the tight manufacturing tolerances necessary in industrial manufacturing when said tool turret is in operation.

The present invention achieves this object with a tool turret having the features specified in claim 1 in its entirety.

Since the drive device is arranged, according to the characterizing part of claim 1, inside the tool disk together with the drive means and the output means, used to drive the machining tool, while the output means, used to drive the tool disk in a swiveling manner, have a gear train arrangement, which may be found outside the tool disk on the support column, and the gear train arrangement has an output shaft that extends along the support column, the result is an extremely compact design of the whole system of the tool turret, consisting of a tool disk and a support column. Since the output means for driving the tool disk in a swiveling manner are arranged with the gear train arrangement and the output shaft outside the tool disk on the support column, the tool disk can be designed to be extremely compact, even though it houses a common drive for swivel motions and the drive of a rotary tool. In this case, the latter is used, as it were, as the direct drive of the machining tool, while the swivel drive is shifted to the support column with the result that the mass of the gear train arrangement of the swivel drive does not act on the mass of the tool disk itself.

It is highly advantageous that the gear train arrangement can have a Wolfrom planetary gear. Since a Wolfrom planetary gear will ensure a very high transmission ratio even in the case of the smallest possible space requirement, the support column, too, needs only a small amount of installation space in order to transform the relatively high speed of the drive shaft of the drive device, as required for the direct drive of the machining tool, into the comparatively low speed of the output shaft provided for the swivel drive.

In the case of drive means, which can be driven by a common drive shaft of the drive device, the coupling device for the selective coupling with the drive means for the swivel drive and with the drive of the machining tool can be controlled by an actuating device, by means of which the respective drive means can be displaced coaxially to the drive shaft of the drive device or parallel thereto. A coaxially displaceable arrangement of the respective drive means relative to the drive shaft has only, on the one hand, a minimum installation space requirement; and in addition, the coaxial arrangement permits the drive shaft of the drive device to directly drive the drive means with zero backlash.

In a preferred exemplary embodiment, the second drive means is arranged coaxially to the first drive means inside the receiving space in the tool disk. The coaxial arrangement of the second drive means to the first drive means permits a space saving design.

In a preferred exemplary embodiment, the coupling device, comprising the two drive means, is mounted on the drive shaft in a rotationally rigid manner and can be displaced axially relative to said drive shaft. The rotationally rigid connection of the coupling device to the drive shaft ensures the transmission of the torques from the drive device to the coupling device. The axial displaceability of the coupling device on the drive shaft makes it possible to provide assigned axial positions of the coupling device for the selective drive of the tool disk or the machining tool.

In a preferred exemplary embodiment, the actuating device of the coupling device consists of a hydraulic cylinder, which is surrounded at least in sections by the drive shaft and in the actuated state feeds the drive means inside the receiving space in the direction of the output shaft of the machining tool to be driven and in the non-actuated state feeds in the opposite direction for the swivel drive of the tool disk. The implementation of the actuating device by means of a hydraulic cylinder supports a compact design. Moreover, this arrangement ensures for the cylindrically configured drive means that a uniformly distributed infeed force can be applied in a ring-shaped manner to said drive means by the hydraulic cylinder, so that a canting or blocking of the drive means during the infeed operation is largely ruled out.

A preferred exemplary embodiment provides that the tool disk can be secured in a defined manner in its predefinable swivel positions relative to the support column by means of a locking device. A defined securing in predefinable swivel positions is absolutely mandatory for machining workpieces with a high degree of precision, because, for example, in machining operations very high forces may occur at the machining tool. Even under such loads, the machining tool, which is fastened to the tool disk by means of the holding mechanism, remains stable in its intended position owing to the locking device. An especially advantageous embodiment can provide for the locking device, a so-called Hirth coupling, that in the case of a very stable locking in the locked state allows a nevertheless adequately high resolution swiveling of the tool disk.

With respect to an extremely compact design of the support column, the arrangement can be configured in such a way that hollow shafts that extend coaxially to each other along the support column form the drive shaft and the output shaft of the Wolfrom planetary gear that may be found at a distance from the tool disk.

The invention is explained in detail below by means of one exemplary embodiment depicted in the drawings. Referring to the drawings:

FIGS. 1A and 1B show a center section of the exemplary embodiment of the tool turret, where FIG. 1A shows the region of the tool disk with an adjoining part of the support column; and where FIG. 1B shows the remaining section of the support column;

FIG. 2 is a sectional view (drawn slightly larger than in FIG. 1) of just that part of the tool disk that faces the holding mechanism of a machining tool with the adjacent support column, whereby the operating state of the activated swivel drive of the tool disk is shown; and

FIG. 3 is a perspective detail view (partially cut open) of the tool disk, whereby the operating state of the activated swivel drive is shown.

In the exemplary embodiment of the tool turret 4 that is shown in the figures, a drive device 14 is provided for the selective swivel drive of a tool disk 2 and the rotary drive of at least one machining tool (not illustrated), which can be fastened to the tool disk 2 by means of a holding mechanism 6. The drive is implemented by means of two drive means 8, 10 that can be driven by the common drive device 14 which has a drive shaft 12. The drive means 8, 10 can be connected to the output means 20, 22 by means of a coupling device 18 that can be controlled by at least one actuating device 16. At the same time, the output means 20 is used to drive the tool disk 2, whereas the output means 22 is used to drive the machining tool. The drive device 14 is arranged completely inside the tool disk 2 together with the drive means 8, 10 and the output means 22, which are used to drive the machining tool, whereas the output means 20, which are used to drive the tool disk 2 in a swiveling manner, are not directly—that is, inside the tool disk 2—in drive connection with this tool disk, but rather are operatively connected to the tool disk 2 by means of a gear train arrangement 34, which may be found outside the tool disk 2 on the support column 32 of the tool turret 4. This gear train arrangement, which is configured in the form of a Wolfrom planetary gear 34 and which is arranged on the support column 32, defining the swivel axis of the tool disk 2, at a distance from the tool disk 2, is described in greater detail below. The drive device 14 is arranged together with the drive means 20, 22 inside the tool disk 2 inside a receiving space 24 of the tool disk 2.

The actuating device 16 permits the respective drive means 8, 10 to be arranged coaxially to the drive shaft 12 of the drive device 14. The coupling device 18, comprising the two drive means 8 and 10, is mounted on the drive shaft 12 in such a way that it is rotationally rigid, but axially displaceable relative to the drive shaft 12 in the direction of the center axis 26 of the coupling device 18.

When the machining tool, which is fastened to the tool disk by means of the holding mechanism 6, is adjusted into a machining position by means of the swivel motion of the tool disk around a swivel axis 28, the coupling device 18 is actuated in such a way that the coupling device 18 is fed from the position shown in FIG. 3 to the right, in order to drive the machining tool by coupling the drive means 8 with the output means 22. On the other hand, in order to drive the tool disk 2 in a swiveling manner, the coupling device 18 is in the axial position that is shown in FIG. 3 and also in the other figures. At the same time, when the coupling device 18 is rotationally moved by the drive device 14, the rotational motion is transferred to a gearwheel 48 by way of the drive means 10, which is in engagement with the output means 20 when the coupling device 18 is in this position. An intermediate gearwheel 50 that meshes with the gearwheel 48 continues the drive connection to the planetary gear 34 that is arranged on the support column 32.

In the depicted exemplary embodiment, the force is transferred from the drive shaft 12 to the coupling device 18 by means of the outer peripheral-side teeth 42 of the coupling device 18 that mesh with the inner peripheral-side teeth 44 in a recess of the drive shaft 12. In order to displace the coupling device 18 into the respective switching or axial positions, the actuating device 16 has a hydraulic cylinder 74.

In order to transfer the force to the planetary gear 34, the intermediate gearwheel 50 is in meshing engagement with a gear rim 52, which may be found on a collar 46 of a hollow shaft 68, said collar being expanded in the manner of a flange. This hollow shaft 68, which surrounds concentrically the support column 32, has an end that faces away from the collar 46 and is in drive connection with a circumferential housing part 62 of the planetary gear 34 by way of a serration 64 (see FIG. 1B). This planetary gear may be found inside a housing part 56 that is rigidly mounted on the support column 32. This housing part defines together with a rotatable housing part 54 a space for at least one planet wheel 40. In this context, the housing part 54 and the housing part 56 form the inner teeth 36 or 38 respectively. The inner teeth 36, 38, which mesh with the at least one planet wheel 40, have a slightly different number of teeth, so that, in accordance with the Wolfrom gear principle, the rotatable housing part 54 has a much lower speed compared to the input speed of the hollow shaft 68.

The circumferential housing part 54 is connected to the output-side hollow shaft 70, which coaxially surrounds the input-side hollow shaft 68. The hollow shaft 70, which can be driven at the greatly reduced speed, is in turn rigidly connected to a receiver disk 71. This receiver disk has an end 76 that faces the tool disk 2 and is connected to the tool disk 2 in order to form the swivel drive for this tool disk. In order to lock the tool disk 2 in a form-fitting manner in the respectively defined swivel position, a locking device 58 is provided in the form of a bolt body, which can be displaced hydraulically, in order to engage and disengage a Hirth coupling 60 that is provided between the locking body and the receiver disk 71. 

1. A tool turret comprising a tool disk (2), which can be swiveled around a support column (32), which defines a swivel axis (26), into positions in which at least one machining tool that is fastened to the tool disk (2) is in a machining position, and comprising a drive device (14) having drive means (8, 10), which can be connected to output means (20, 22), which are used to drive the tool disk (2) or the machining tool, by means of a controllable coupling device (18), characterized in that the drive device (14) is arranged inside the tool disk (2) together with the drive means (8, 10) and the output means (22), used to drive the machining tool, and that the output means, used to drive the tool disk (2) in a swiveling manner, have a gear train arrangement (34), which may be found outside the tool disk (2) on the support column (32); and the gear train arrangement (34) has an output shaft (70) that extends along the support column (32).
 2. The tool turret according to claim 1, characterized in that the gear train arrangement comprises a Wolfrom planetary gear (34).
 3. The tool turret according to claim 1, characterized in that the drive means (8, 10) can be driven by a common drive shaft (12) of the drive device (14).
 4. The tool turret according to claim 1, characterized in that the coupling device (18) can be controlled by an actuating device (16), by means of which the respective drive means (8, 10) can be displaced coaxially to the drive shaft (12) of the drive device (14) or parallel thereto.
 5. The tool turret according to claim 4, characterized in that the second drive means (10) is arranged coaxially to the first drive means (8) inside the receiving space (24) in the tool disk (2).
 6. The tool turret according to claim 5, characterized in that the coupling device (18), comprising the two drive means (8, 10), is mounted on the drive shaft (12) in a rotationally rigid manner and can be displaced axially relative to said drive shaft.
 7. The tool turret according to claim 1, characterized in that an actuating device (16) of the coupling device (18) consists of a hydraulic cylinder, which is surrounded at least in sections by the drive shaft (12) and in the actuated state feeds the drive means (8, 10) inside the receiving space (24) in the direction of the output means (22) of the machining tool to be driven and in the non-actuated state feeds in the opposite direction for the swivel drive of the tool disk (2).
 8. The tool turret according to claim 1, characterized in that the tool disk (2) can be secured in a defined manner in its predefinable swivel positions relative to the support column (32) by means of a locking device (58).
 9. The tool turret according to claim 2, characterized in that the hollow shafts (68, 70) that extend coaxially to each other along the support column (32) form the drive shaft and the output shaft of the Wolfrom planetary gear (34) that may be found at a distance from the tool disk (2). 